1. Field of the Invention
The present invention relates to an image-forming apparatus having a seal for containing a developer in a developing device and method for detecting a removal of the seal. More particularly, the present invention relates to an image-forming apparatus having a replaceable compact developing device with a seal for the developer contained therein and a method for detecting the removal of the seal.
2. Discussion of the Background
In recent years, demand for easily maintainable image-forming apparatuses, such as laser printers, photocopiers or a facsimile machine has increased so the user of such an apparatus can maintain and use the apparatus in a stable condition by themselves instead of calling a service person. For example, it is desired by users of image-forming apparatuses to easily replace by himself or herself used developer, at the end of its life or after being damaged. In addition, as appreciated by the present inventors, that it is desired that a replacing unit or module is compact in size so as to be easily handled during replacing operations.
Japanese Laid-Open Patent Publication No. 03138672 describes an image-forming device that has a photoconductive drum as an image bearer, a developing device providing a magnetic brush roller as a developer beam, and a developer container filled with a developer mix sealed with a seal member. The developing device including the developer container can be relatively easily replaced with new one that is filled with new developer mix by the user of the image-forming device, when the replacement is required. After the new developing device is installed, the seal member is manually removed so that the developer mix in the container moves toward the developer bearer for being used in an image forming operation. However, as recognized by the present inventors, the image forming device does not detect the removal of the seal member and so the user may erroneously skip the manual operation of removing the seal member, and start an image-forming operation. In this scenario, when the seal member is not removed, no developer mix is supplied to the developer bearer, and no developer mix is applied to the image bearer. Consequently, the image-forming device does not form a toner image on the image bearer.
Further, as recognized by the present inventors, when no toner is applied to the image bearer, a doctor blade in a cleaning device for cleaning the image bearer may turn over or chip relatively easily because of the relatively large friction between the doctor blade and the image bearer due to lack of toner as a lubricant, The turning over or chipping may damage not only the doctor blade but also the image bearer, such as by creating scratches on the surface of the image bearer.